Blind Integer Carrier Frequency Offset Estimation for OFDM Systems with Constant Modulus Signaling

This paper presents a blind integer carrier frequency offset (IFO) estimator for the constant modulus (CM) signaling based OFDM systems. The key idea behind this method is a power reallocation technique which modifies the power of data in some predefined subcarriers over two consecutive OFDM symbols, thus the IFO can be estimated in the receiver via analyzing the distribution of these subcarriers. Instead of the exhaustive search, a low-complexity algorithm is proposed. The selection criterions of these predefined subcarriers are carefully designed and more than two OFDM symbols are employed to improve the robustness of this method to the multipath effect. Furthermore, this method can be applicable in multiple-input multiple-output (MIMO) OFDM systems with the orthogonal space-time block coding (OSTBC).